Lightning-arrester.



P. M; BUTLER.

LIGHTNING AREESTER. APPLICATION FILED JAN. 21, 1910.

969,336. Q Patentedsept. 6, 1910..

FABIUS M. BUTLER, OF DAVID CITY, NEBRASKA.

LIGHTNING-ARREST ER.

Specification of Letters Patent.

' Patented Sept 6, 1910.

Application filed January 21, 1919. Serial 110. 539,228.

To all whom it may concern:

Be it known that I, FABIUS M. BUTLER, a.

citizen of the United States, residing at David City, in the county of Butler and State of Ne raska, have invented a new and useful Lightning Arrester, of which the following is a specification.

This invention has reference to improvements in lightning arresters and its object is to provide a self adjusting lightning errester which will not burn or get dirty and wherein the contact terminals will not'corrocle.

The invention will be best understood from a consideration of the following detail description taken in connection with theseconipanying drawings, forming a. part of this specification, in which drawings,

Figure l is :t perspective View 0:5 the lightning art-ester with the ports separated. Fig. 2 is a longitudinal section with the parts ossemblecl. Fig. 3 is a. perspective View of a. slightly different form than that shown in l and 2.

In the structure shown in. Figs. 1 and 2 there are provided two blocks and 2 each having formed in one end chember 3. There is also provided a division piste l through which there is formed a slot nearer to one edge of the plate then the other and matching the openings of the chambers 3 of the blocks l and The slot 5 is so positioned in the plate l that when the parts are assembled the slot will match a. portion only or" the openings into the chambers While the remainder of the openings into the ehmubers is covered by a portion 6 of the plate immediately adjacent to the slot 5.

\Vhen the warts are assembled as shown in Fig. 2 the plate 4* is confined between contiguous feces oi the blocks 1 and 2 and the portion (3 of the plate forms a division Wall between the two chambers and projects from the bottom ot' the chamber, the blocks 1 and 2 being assumed to be horizontally disposed, to near the tops of the chambers so that only the upper portions of the chambers have communication by slot 53.,

The blocks 1 and 2 and the plate t may be made of suitable insulating material, preferably refractory insulating material or the blocks 1 and 2 may be made of carbon or of suitable metal and the plate 4 be made of in suluting material and the chambers 3 in the l two blocks are partly filled With masses 7 of mercury.

brought into contact with certain surfaces there is surface repulsion so that the mercury rounds up away from such surfaces and itscentral portion is sensibly more elevated than where contacting with the said surfaces. This characteristic of mercury is utilized in connection with the present invention and the mercury masses 7 are made sulliciently deep so that the adjacent por tions where engaging the surfaces of the portion 6 of plate l rise above the lower edge of slot 5 so that the mercury inussos are separated by a direct air gap but slightly greater than the thickness of the phite -l.-.

Conductors 8 are introduced through the blocks 1 and 2 into the ends of the chambers 3 remote from the plates at although of course the particular location of the conductors as shown and described is not mandatory and these conductors may enter the chambers 3 in other directions. Of course the ends of the conductors 8 where engaging the mercury are made of e. material to which mercury is inert.

The blocks 1 and 2 with the intervening plate 4 may be firmly clamped togetherby means of llUliH or screws 9 indicated in Fig.

ore of conducting material sulateol therefrom.

If one of the conductors 8 be connected to the instrument or circuit to be protected and the other conductor 8 be grounded, where the structure is used a lightning arrester. or if the structure be introduced in a circuit in any other of the usual modes of protecting electrical instruments or lines, then on the passage of a current of sulfi- -iontly high potential the resistance of the air gap botwron the rounded up edges of the mercury masses '2 on the opposite sides of the plate 4 at the slot 5 will be broken down and current will pass from one mass of mercury to the other in :1. manner common to lightning urresters and instruments of such character.

lVhen the discharge :cases the mercury on ("recount of its extreme mobility will int-- nicdiutcly return to the former condition and the apparatus is ready for the passage of another such discharge. Because of the large surface presented and because of the are suitably inltis a peculiarity of mercury that Where I, and these hulls or screws when the bloelis' the terminal surfaces.

character of mercury there is no danger of burning of the terminals since there 1s a constant presentation of new surfaces and for the same reason there is no corrosion'of Since the mercury masses return to their normal condition immediately on the cessation of a discharge over the air gap through the slot or passage 5, the device is self setting and will maintaln its efiiciency for a long period of time Without attention.

In Fig; 3 there is shown another form of the invention where the blocks 1 and 2 and the plate 4: are replaced by a single block 10 having its interior formed into two chambers by an intermediate diaphragm 11 of less height than the outer walls of the container 10 and a suitable cover 12 may be applied although this cover is not necessary for the operation of the device and if desired may be omitted. The division wall 11 may be molded in one piece with the rest of the block if the block be made of moldable material.

The lightning arrester may be coupled up in electric circuits in any suitable manner.

What is claimed is 1. Alightning arrester comprising a receptacle having chambers or cavities separated by a Wall of less height than the depth of the cavities said cavities each containing mercury and circuit terminals entering the cavities lnto electrical contact with the mercury.

2. A lightning arrester comprising a receptacle having chambers or cavities separated by a wall of less height than the depth of the cavities, each cavity containing mercury to a maximum depth greater than the height of the division wall, and circuit terminals entering the cavities into electrical contact with the mercury.

3. A lightning arrester comprising blocks of suitable material each with a chamber or cavity secured therein, a division plate of insulating material provided with a passage there-through and located between the chamber'ed blocks with thepassage constituting a communication between the chambers or cavities at the upper portions thereof, and mercury in the cavities to a maximum depth greater than the height of the division plate where separating the cavities.

In testimony that I claim the foregoing as my own, I have hereto ailixed my signature in the presence of two witnesses.

FABIUS M. BUTLER.

lVitnesses: I

J B. PosrEsEL, J K. MASHEK. 

